Thursday afternoon, US President Donald Trump reacted to former FBI director James Comey’s Senate testimony by telling an audience of his supporters, “We are under siege.”He was right.Trump and his presidency are besieged by an army of investigators whose apparent goal is to delegitimize, with the goal of destroying, his presidency.This was the lesson of Comey’s testimony on Thursday before the Senate Intelligence Committee.Comey came before the committee to share his assessment of the connection between his firing last month and the FBI’s ongoing investigation of ties Trump, his advisers and associates maintained with Russian agents during the 2016 elections and the transition period that preceded his inauguration on January 20.Despite the fact that the investigation was launched well before the November election, no evidence has surfaced of criminal wrongdoing by Trump or his associates.So what purpose does the investigation serve? Among the important things Comey shared on Thursday was the answer to that question. The first important piece of information Comey shared was that Trump is not and never has been under investigation.Second, Comey told us he views Trump as a uniquely unacceptable president. Whereas Comey kept no notes of his meetings with former president Barack Obama; and whereas he wrote no summaries of his meetings with former president George W. Bush, Comey said that he wrote summaries of all of his communications with Trump.Comey explained the disparity by noting, repeatedly, that he views Trump as singularly untruthful.This is notable because, as Comey made clear Thursday, in everything related to the two men’s dealings since November, it has been Comey, not Trump, who has been deliberately misleading.In his termination letter to Comey last month, Trump wrote that Comey had informed him three times that he was not under investigation.And yet, in his March testimony before the Senate, Comey refused to admit that Trump was not a subject of investigation. To the contrary, Comey’s statement on the issue was deliberately vague and therefore misleading.Even more damning, Comey admitted Thursday that he used a friend as a conduit to leak selected, and as it turns out, misleading, portions of his memo summarizing a meeting he held with Trump in February to The New York Times.The article that the Times published on the basis of that memo alleged that during that conversation, Trump pressured Comey to close his criminal investigation of Trump’s former national security adviser Lt.- Gen. Michael Flynn. During his testimony Thursday, Comey admitted under questioning that Trump did no such thing; Trump merely expressed his hope that Flynn would be cleared of criminal suspicion.In other words, it was Comey, not Trump, who lied about the contents of their meeting.Finally, and most crucially, Comey explained that he deliberately misled the public about Trump’s statements to him through his selective leak to the Times in order to achieve a political goal.“I asked” my friend to communicate the contents of the memo with a reporter “because I thought that might prompt the appointment of the special counsel,” Comey said.Indeed, the media storm set off by the Times’s story compelled Deputy Attorney-General Rod Rosenstein to appoint Comey’s close personal friend, former FBI director Robert Mueller, to serve as a special counsel.Mueller’s mandate is expansive. Not only is he empowered to investigate “any links and/or coordination between the Russian government and individuals associated with the campaign of President Donald Trump,” he is also empowered to investigate “matters that arise or may arise directly from the investigation and other matters within the scope of [the federal statute governing special counsels].”In other words, Mueller is empowered to investigate anything he wants. He can charge people for illegal ties with Russia. And he can charge people who did nothing wrong with obstructing his investigation if he doesn’t like the way they answer his questions on Russia.And, Mueller can keep the investigation open forever, keeping the pall of criminality over Trump’s presidency until the day he leaves office even if Mueller never indicts anyone.So what can Trump do? As former House speaker Newt Gingrich and others argued following Comey’s testimony, Trump can and should fire Mueller.Since Comey’s manipulative and misleading leak fomented Mueller’s appointment, and since Mueller is Comey’s close friend, Mueller cannot credibly be considered an impartial investigator.Finally, since Trump is not under investigation, and given that both the House and the Senate are carrying out separate investigations into the same alleged collusion between Trump’s associates and the Russian government, there is no rationale for a third investigation by a special counsel.Beyond firing Mueller, Trump should move immediately to appoint a special counsel to investigate allegations of criminal wrongdoing by Obama administration officials.Whereas Republican lawmakers are cooperating with Democratic lawmakers in the congressional probes against Trump and his campaign officials, Democratic lawmakers refuse to cooperate with their Republican counterparts in investigating any aspect of suspected illegal behavior by Obama administration officials.Consider the case of former attorney-general Loretta Lynch.Comey served up Lynch on Thursday when he told the Senate that she had instructed him not to refer to the criminal probe of then-secretary of state Hillary Clinton’s transfer of State Department documents, including classified documents to her private Internet server, as an investigation. Instead, in line with the language used by the Clinton campaign to diminish the significance of the probe, Lynch instructed Comey to refer to the investigation as “a matter.”Comey’s statement alone provided the basis for a criminal probe of collusion between the Obama Justice Department and the Clinton campaign.Then there is the issue of alleged abuse of NSA intercepts by senior Obama administration officials to spy on US citizens.Given the Democrats’ stonewalling of their Republican colleagues, it would be eminently sensible for Trump to appoint a special counsel with the power to investigate all aspects of alleged unlawful spying on US citizens allegedly conducted by the Obama administration.Finally, and most importantly, the time has come for Trump to recognize that he is no longer running for office and to begin to use the powers of the presidency presidentially.The most urgent aspect of this is for Trump to fill the thousands of federal positions that are now being filled by Obama’s political appointees.Once Trump hires professionals not loyal to Obama to fill mid-level and senior positions, the deluge of classified material daily making its way to the media will dry up. People who support, or at a minimum do not oppose, Trump’s presidency will have no impetus to abuse their positions to damage his presidency.Staffing the federal government with people who do not hate Trump will also enable him to implement his presidential agenda far more effectively than he has to date. And that’s the thing of it: In areas that Trump has managed to advance his agenda – for instance, during his trip last month to the Middle East and Europe – he has been tremendously successful.So too his legislative agenda is working its way through Congress. Although it is taking longer than he had hoped, it, too, is likely to pass. Lastly, Trump should recognize that governing and running for office are two different things.When Trump went on the offensive against his Republican rivals in the primaries and against Clinton in the general election, he was punching up. He was empowered by those attacks, while his more established rivals were diminished when they responded.The moment he swore the oath of office, Trump’s position changed. Now when he attacks his opponents, he diminishes himself and empowers them. When he says that Comey is a liar, he expands Comey’s importance.It is time for Trump to delegate the dirty work of attacking his opponents to his attorneys, advisers and supporters. He must devote his public appearances entirely to advancing his own presidential agenda.By firing Mueller, appointing a special counsel to investigate the Obama administration, removing Obama’s political appointees from government and replacing them with his own hires, and concentrating on implementing his agenda, Trump will end the siege on his presidency. He will defeat the self-proclaimed “resistance” whose purpose is to defeat him politically through administrative and bureaucratic abuses.Whether Trump’s presidency will eventually be successful will still be an unanswered question. But, at the very least, it will finally get off the ground.